Codeigniter 三表连接，显示图片问题

Question

我正在使用 CodeIgniter PHP 框架和 MySQL 作为数据库。我想显示房间的具体平面图（img）也显示没有房间的建筑物。

我有 3 张桌子：

tblbldg - 建筑

• id (pk)
• 姓名

tblroom - 房间

• 身份证
• 姓名
• 地板
• building_id (fk)

tblfloorplan - 平面图

• 身份证
• 地板
• building_id (fk)
• img

我尝试了这段代码，但它最终混合了 img，比如 building1 floor1 显示与 building 2 floor1 相同的平面图：

public function get_rooms(){
    $this->db->select('tblroom.id,
        tblroom.name,
        tblroom.floor,
        tblbldg.name as building_name,
        tblfloorplan.img');
    $this->db->from('tblroom');
    $this->db->join('tblbldg',"tblbldg.id = tblroom.building_id");
    $this->db->join('tblfloorplan',"tblfloorplan.floor = tblroom.floor");
    return $this->db->get();
}

Answer 1

试试这个，

public function get_rooms(){
       $this->db->select('tblroom.id,
            tblroom.name,
            tblroom.floor,
            tblbldg.name as building_name,
            tblfloorplan.img');
        $this->db->from('tblroom');
        $this->db->join('tblbldg',"tblbldg.id = tblroom.building_id");
        $this->db->join('tblfloorplan',"tblbldg.id = tblfloorplan.building_id and tblfloorplan.floor = tblroom.floor");
        return $this->db->get();
    }